61574-53-6Relevant articles and documents
Synthesis and aggregation properties of a new family of amphiphiles with an unusual headgroup topology
Stein, Thomas M.,Gellman, Samuel H.
, p. 3943 - 3950 (1992)
A new family of amphiphiles, derived from a rigid dicarboxylic acid headgroup unit of unusual topology, has been synthesized. The aggregation of these molecules in aqueous solution has been examined by 1H NMR and dye solubilization methods. Two modes of aggregation appear to be operative within this group of amphiphiles, one determined by the headgroup and the other determined by the flexible tail. The former mode is dominant when the tail is short or nonexistent, and the latter is dominant when the tail contains six or more nonpolar atoms. The latter mode appears to be a typical micellization process, but the former is less cooperative. For the latter group of amphiphiles, comparison with literature data for a family of long chain alkyl malonate surfactants indicates that the wide, rigid headgroup, containing 16 non-carboxylate carbon atoms, has the equivalent "hydrophobic impact" on aggregation of only five CH2 groups in the flexible tail.
Preparative methodology and pyrolytic behavior of anthrylmonocarbenes: Synthesis and chemistry of 1H-cyclobuta[de]anthracene
Kendall, J. Kirby,Engler, Thomas A.,Shechter, Harold
, p. 4255 - 4266 (2007/10/03)
This study involves (1) the behavior of organolithium reagents (1-6), (2) development of efficient methods for preparing 9(7)- and 1(8)- [methoxy(trimethylsilyl)methyl]anthracenes and their analogues, (3) the intramolecular chemistry of the 9(9)- and 1(10)-anthrylcarbenes generated by pyrolyses of 7 and 8, respectively, and (4) investigation of thermal behavior and bromination of the 1H-cyclobuta[de]anthracene (11) obtained from 9 or 10. α-Methoxy-9-anthrylmethyllithium (1), prepared from 9- (methoxymethyl)anthracene (14) and t-BuLi in TMEDA/Et2O/pentane, reacts at C-10 with D2O, chlorotrimethylsilane, dimethyl sulfate, benzoyl chloride, acetaldehyde, benzaldehyde, and acetone to give, after neutralization, 9,10- dihydro-9-(methoxymethylene)-10-substituted-anthracenes 15 and 21a-f. However, lithiation of 9-(thiomethoxymethyl)anthracene (25) with t- BuLi/TMEDA/Et2O/pentane occurs by an apparent radical-anion displacement process to give 9-anthrylmethyllithium (3), which then reacts with chlorotrimethylsilane to yield 9-(trimethylsilylmethyl)anthracene (28). Similarly, 28 is formed from 25 and from 9- (trimethylsilyloxymethyl)anthracene (29) with lithium and then chlorotrimethylsilane. The electrophiles D2O, dimethyl sulfate, and benzaldehyde react with 3 at its methyl and its C-10 positions. [Methoxy(trimethylsilyl)methyl]arenes 40-42 and 7 are obtained by reactions of their aryllithium and arylmagnesium bromide precursors with bromo(methoxy)methyltrimethylsilane (39). 1-(Methoxymethyl)anthracene (45) is converted conveniently by t-BuLi and chlorotrimethylsilane to 8. Flash- vacuum pyrolyses of 7 and 8 yield 11 preparatively; 11 then thermolyzes to 2H-cyclopenta[jk]fluorene (46). Decomposition of 9-deuterio-10- [methoxy(trimethylsilyl)methyl]anthracene (55) at 650 °C/10-3 mm results in 10(56)- and 1(57)-deuteriocyclobutanthracenes, thus revealing that the 10- deuterio-9-anthrylcarbene inserts to give 56 and also isomerizes extensively before yielding 57. Of note is that 56 isomerizes thermally by C10-D movement to form 2-deuteriocyclopentafluorene 58, 57 rearranges by C10-H movement to yield deuteriocyclopentafluorene 59, and 58 and 59 equilibrate 1,5-sigmatropically. Possible mechanisms for the isomerizations of 56 and 57 are outlined. Further, bromine adds rapidly to 11 to form 9,10-dibromo-9,10- dihydro-1H-cyclobuta[de]anthracene (94), which eliminates HBr on warming to yield 10-bromo-1H-cyclobuta[de]anthracene (95).
